Industrial robots are machines which can be equipped for automatically handling and/or processing objects with tools, and which can be programmed by means of their joints in multiple axes of motion, for example, with regard to orientation, position and workflow. Industrial robots usually have a multi-axis robot arm, which can be automatically and manually adjusted especially by electric motors, and a programmable controller (control device), which controls or regulates the movements of the industrial robot during the operation.
Robot arms essentially comprise a frame and a carousel which is pivoted about a rotation axis in relation to the frame. Mounted to said carousel is a rocker arm which, in turn, is mounted to a robot arm boom with a robot hand, in which the robot arm boom and/or the robot hand can have multiple joints. Depending on the constructive design of the robot arm, the potential rotary motions of one or multiple joints or robot axes can be mechanically defined by fixed stops to less than 360°, or can be defined by fixed stops to more than 360°, for example, to between 380° and 420°.
To allow the carousel to rotate more than 360° in relation to the frame, the DE 296 16 401 U1 discloses an industrial robot which comprises a frame having a partially annular connecting link arranged concentric to the rotation axis which connecting link has a slidably mounted trailing stop. The carousel comprises an engaging piece which interacts in one rotational direction of the carousel with one side of the trailing stop when reaching the connecting link, and in the opposite direction interacts with the opposite side, and which always carries the trailing stop up to the stop at the opposite side of the connecting link. The trailing stop can be provided on all sides, or merely on the sides affected by impact and friction with a dampening coat, for example, in the form of vulcanized rubber. To avoid that the trailing stop is tilted but is smoothly guided across the sliding surface, the trailing stop requires a specific width.
The DE 10 2009 043 404 A1 discloses an industrial robot which has a multi-axial robot arm with a frame, a carousel pivoted about an axis in relation to the frame, and a mechanical stop device provided for defining a rotary motion of the carousel in relation to the frame. Said stop device comprises a connecting link arranged at the frame, which connecting link has stops on its ends, a trailing stop arranged in the connecting link, and an engaging piece arranged at the carousel, wherein the engaging piece and the connecting link are designed in such a way that the engaging piece is inserted in the connecting link when the horizontal rotating table is rotating about the axis and is pushing the trailing stop against the relevant stop. The trailing stop comprises a plastically malleable damping element which is provided to decelerate the horizontal rotating table by means of the engaging piece when because of plastic deformation the trailing stop pushes the relevant stop.